Power System Checkout; Checking The Ac Power Adapter - Lenovo ThinkPad X240 Hardware Maintenance Manual

1. Go to:
http://www.lenovo.com/diags.
2. Click Lenovo Bootable Diagnostics.
3. Follow the instructions on the Web site to create a bootable diagnostic medium on a USB device or CD.
To use the diagnostic medium you have created, do one of the following:
• If you have created the bootable diagnostic medium on a USB device, do the following:
1. Attach the USB device to the computer.
2. Turn on the computer. If the computer cannot be turned on, go to "Power system checkout" on page
26, and check the power sources. If an error code is displayed, go to "Symptom-to-FRU index" on
page 35 for error code descriptions and troubleshooting hints.
3. When the ThinkPad logo is displayed, repeatedly press and release the F12 key. When the Boot
Menu window opens, release the F12 key.
4. Use the arrow keys to select USB HDD and then press Enter. The diagnostic program will be
launched automatically.
5. Follow the instructions on the screen to use the diagnostic program.
• If you have created the bootable diagnostic medium on a CD, do the following:
1. Turn on the computer. If the computer cannot be turned on, go to "Power system checkout" on page
26, and check the power sources. If an error code is displayed, go to "Symptom-to-FRU index" on
page 35 for error code descriptions and troubleshooting hints.
2. Insert the CD into the external optical drive.
3. Restart the computer.
4. When the ThinkPad logo is displayed, repeatedly press and release the F12 key. When the Boot
Menu window opens, release the F12 key.
5. Use the arrow keys to select ATAPI CDx (x: 0, 1, ...) and then press Enter. The diagnostic program
will be launched automatically.
6. Follow the instructions on the screen to use the diagnostic program.

Power system checkout

To verify if the battery packs and the power adapter are functional, do the following:
1. Turn off the computer.
2. Connect the ac power adapter.
3. Turn on the computer. If the computer can be turned on, it means that either the battery pack or the ac
power adapter is functional.
4. Insert a straightened paper clip into the emergency reset hole to reset the computer. If the computer is
still powered on, it means that the ac power adapter is functional.
5. Turn off the computer.
6. Disconnect the ac power adapter and turn on the computer. If the computer can be turned on, it
means that the battery pack is functional.
If you suspect that the power problem is caused by a specific power device, refer to the appropriate
checkout item in the following list:
• "Checking the ac power adapter" on page 26
• "Checking operational charging" on page 27
• "Checking the coin-cell battery" on page 28

Checking the ac power adapter

You are here because the computer fails only when the ac power adapter is used.
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Hardware Maintenance Manual